Expression Cloning of Host Factors Required for the HCV Replication Cycle

Chronic infection with the hepatitis C virus (HCV) is a common cause of chronic liver disease, cirrhosis, and liver cancer. Like most viruses, HCV depends of a number of factors encoded by its host cell to execute its replication cycle and create. Expression cloning is one of several possible approaches that have been employed to identify novel host factors essential for the HCV replication cycle. It involves generation of a cDNA library from a cell type with a desired trait (such as ability to bind E2 or being susceptible to HCV infection), expression of that library in a different cell type missing the trait of interest, and selection for cell clones that have acquired that trait through expression of a specific cDNA. This chapter describes an expression cloning approach similar to the one that was used to identify the tight junction component claudin-1 as an essential HCV cell entry factor.